Benedict Cumberbatch, Adam Scott join Johnny Depp in 'Black Mass'

Benedict Cumberbatch and Adam Scott joined Johnny Depp on Wednesday as part of the cast of the Whitey Bulger crime drama Black Mass.

Cumberbatch stepped in to replace Guy Pearce, who was forced to back out because of scheduling issues, Cross Creek Pictures president Brian Oliver told Variety. "We were not able to make it work with Guy."

Sherlock star Cumberbatch will play the role of Bulger's brother Billy Bulger, who opted not to follow his brother into organized crime in Boston. Depp, who at one point left the project, plays Whitey.

Whitey was a Boston mobster, who was recently sentenced to two consecutive life sentences as well as an additional five years. He was convicted in November on 31 charges of extortion, weapons charges, money laundering and racketeering.

Scott was cast to play Robert Fitzpatrick, an FBI agent, according to The Hollywood Reporter, who first learned of his casting. Scott joins Joel Edgerton, who is playing FBI Agent John Connolly. Others in the cast include Juno Temple, Dakota Johnson and Jesse Plemons.

Black Mass began shooting in Boston on Wednesday under director Scott Cooper, based off Mark Mallouk's screenplay. The film was inspired by Dick Lehr and Gerard O'Neill's book Black Mass: The True Story of an Unholy Alliance Between the FBI and the Irish Mob.